Field
The described embodiments relate to techniques for adaptively providing collision or contention protection in a wireless network. In particular, the described embodiments relate to techniques for adaptively enabling pre-authorization messages prior to communication in a wireless network based on a packet error rate.
Related Art
Many electronic devices are capable of wirelessly communicating with other electronic devices. For example, these electronic devices can include a networking subsystem that implements a network interface for: a cellular network (UMTS, LTE, etc.), a wireless local area network (e.g., a wireless network such as described in the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard or Bluetooth™ from the Bluetooth Special Interest Group of Kirkland, Wash.), and/or another type of wireless network.
The performance during wireless communication among electronic devices can vary significantly over time. In principle, providers of the electronic devices and operators of wireless networks can adapt the communication to address changes in performance. For example, as shown in FIG. 1, which provides an illustration of communication among electronic devices 110 in an existing wireless network, electronic device 110-3 may not be within communication range of electronic device 110-1. However, electronic device 110-3 may be within communication range of electronic device 110-2, as is electronic device 110-1. Thus, as far as electronic device 110-1 is concerned, electronic device 110-3 may be a hidden node in the wireless network.
If electronic devices 110-1 and 110-3 concurrently attempt to transmit information to electronic device 110-2, a collision or conflict may occur. The resulting interference may degrade the performance during the wireless communication in the wireless network, and may result in retries and increased latency.
One approach for addressing this problem is to have electronic devices 110-1 and 110-3 transmit pre-authorization messages to electronic device 110-2, and to wait for authorization responses from electronic device 110-2 prior to attempting to transmit information to electronic device 110-2. For example, in the context of Wi-Fi® (from the Wi-Fi Alliance of Austin, Tex.), electronic devices 110-1 and 110-3 may transmit request-to-send messages and may wait to receive clear-to-send messages from electronic device 110-2 prior to transmitting the information to electronic device 110-2. Because electronic device 110-2 is within communication range of electronic devices 110-1 and 110-3, electronic device 110-2 can ‘see’ both of these electronic devices. Consequently, there is no hidden node as far as electronic device 110-2 is concerned, and the conflict or collision can be avoided.
However, the pre-authorization messages add overhead and, thus, reduce the communication capacity in the wireless network. Consequently, even though they can offer protection from collisions and conflicts, such pre-authorization messages are often not used, which results in variations in communication performance that may degrade the user experience when using electronic devices 110.